chore(deps-dev): bump opencv-python (#508)

Bumps the pip group with 1 update in the / directory: [opencv-python](https://github.com/opencv/opencv-python).


Updates `opencv-python` from 4.8.0.74 to 4.8.1.78
- [Release notes](https://github.com/opencv/opencv-python/releases)
- [Commits](https://github.com/opencv/opencv-python/commits)

---
updated-dependencies:
- dependency-name: opencv-python
  dependency-version: 4.8.1.78
  dependency-type: direct:development
...

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Author: dependabot[bot]

setup.py

@@ -29,7 +29,7 @@
     packages=find_packages(exclude=("tests",)),
     # create optional [desktop]
     extras_require={
-        "desktop": ["opencv-python==4.8.0.74"],
+        "desktop": ["opencv-python==4.8.1.78"],
         # Local HEIC/HEIF decoding. Opt-in because pillow-heif's binary wheels
         # bundle the x265 encoder, which makes them GPL-2.0 (#398).
         "heic": ["pillow-heif>=1.7.0"],